Ets-1 Targeted by MicroRNA-221 Regulates Angiotensin II-Induced Renal Fibroblast Activation and Fibrosis

• Published in: Cellular physiology and biochemistry Vol. 34; no. 4; pp. 1063 - 1074
• Main Authors: Di, Jia, Jiang, Lei, Zhou, Yang, Cao, Hongdi, Fang, Li, Wen, Ping, Li, Xiurong, Dai, Chunsun, Yang, Junwei
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Cell Physiol Biochem Press GmbH & Co KG 01.01.2014
• Subjects: Angiotensin II; Angiotensin II - genetics; Angiotensin II - metabolism; Animals; Cell Line; Cell Proliferation - genetics; Down-Regulation - genetics; Female; Fibroblast; Fibroblasts - metabolism; Fibronectins - metabolism; Fibrosis - genetics; Fibrosis - metabolism; Gene Expression - genetics; Kidney - metabolism; Kidney Diseases - genetics; Kidney Diseases - metabolism; Mice; Mice, Inbred BALB C; microRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Original Paper; Proto-Oncogene Protein c-ets-1 - genetics; Proto-Oncogene Protein c-ets-1 - metabolism; Rats; Renal fibrosis; Up-Regulation - genetics; microRNA; Angiotensin II; Renal fibrosis; Fibroblast
• ISSN: 1015-8987; 1421-9778
• DOI: 10.1159/000366321

Background: Fibroblast activation is one of the most important mechanisms for Angiotensin II (Ang II) in promoting renal fibrosis. Transcription factor Ets-1 is recognized to play a key role in kidney diseases. However, the role and mechanisms of Ets-1 in Ang-II induced fibroblast activation and kidney fibrosis are not fully understood. Methods: Mice were treated with Ang II via osmotic mini-pumps or Ang II expression plasmid (pAng II). Cultured normal rat kidney interstitial fibroblast (NRK-49F) cells were incubated with Ang II. Role of Ets-1 in renal fibrosis and fibroblast activation were assessed by Western blot, Immunohistochemical staining‚MTT, Boyden chamber and Immunofluorescence staining. Effects of miR-221 on Ets-1 and fibroblast activation were investigated by MTT, Boyden chamber, Western blot and Q-PCR. Results: We found that Ets-1 was up-regulated in fibrotic kidneys. Similarly, Ang II could activate NRK-49F cells as demonstrated by up-regulated α-SMA and fibronectin(FN) expression and enhanced cell proliferation and migration. Ang II also induced Ets-1 expression in NRK-49F cells in a dose and time dependent manner. Knock-down of Ets-1 by RNA interference attenuated Ang II-induced activation of NRK-49F cells. Ets-1 was previously reported as a target of microRNA-221 (miR-221). In Ang II-induced fibrotic kidney, miR-221 was down-regulated. Similar results were observed in Ang II treated NRK-49F cells. Ectopic expression of miR-221 mimic attenuated the up-regulation of Ets-1 by Ang II in NRK-49F cells, which further prevented the activation of NRK-49F cells. However, the inhibitor of miR-221 aggravated Ang II induced Ets-1 expression and NRK-49F cells activation. Conclusions: Our study suggests that miR-221/Ets-1 axis takes an important role in mediating AngII induced interstitial fibroblast activation and renal fibrosis.